A new method to control the free spectral range (FSR) of a long-period fiber grating (LPFG) is proposed and theoretically analyzed. As the refractive index decreases radially cutward in the silica cladding by graded doping of fluorine, waveguide dispersion in the cladding modes was modified to result in the effective indexes change and subsequently the phase-matching conditions for coupling with the core mode in a LPFG. Enlargement of the FSR in a LPFG was theoretically confirmed.
Bibliographical noteFunding Information:
Manuscript received October 14, 2002; revised March 31, 2003. This work was supoorted in part by the Korea Science and Engineering Foundation (KOSEF) through the Ultra Fast Optical Network (UFON) Engineering Research Center (ERC) program in Kwangju Institute of Science and Technology (K-JIST), the Brain Korea21 (BK21) program supported by the Ministry of Education (MOE), and the Center for Hybrid Optical Access Network (CHOAN) Information Technology Research Center (ITRC) program supported by the Ministry of Information and Communication (MIC).
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics